Noongar Indigenous leaders have filed a compensation claim against West Australia's government that could become one of the world's biggest legal payouts.
Noongar people of southwest WA are pursuing more than $290 billion for "spiritual damage" caused by loss of their traditional land.
The figure would be almost a quarter of Australia's gross domestic product of $1.4 trillion and more than West Australia's gross state product of $259 billion.
If the action is successful, it would put it in the range of a landmark $US206 billion ($304 billion) payout made by the tobacco industry to governments across the United States in 1998.
Noongar woman Naomi Smith, a lead claimant, said her people had been struggling since European settlement when they lost access to their traditional land.
She said this claim was seeking reimbursement for the extinguishment of their native title rights over vast swathes of their country.
"It's going to be huge in regard to what Noongar people could do for our Noongar kids," she said.
David Stevenson, the solicitor representing Ms Smith, said it was "far and away" the largest claim made in Australia.
"It's effectively the largest litigation and largest compensation claim in the world," he said.
In 2008, the traditional owners were granted native title over 19.7 million hectares of land, an area almost the size of Victoria.
But their rights to the vast majority of this land, 19.4 million hectares, have been "extinguished" because it was now used as government land, or for commercial, residential, agricultural or mining purposes.
This extinguishment meant the Noongar people were no longer able to exercise their traditional rights on the country.
"This is about our cultural and spiritual damage, as all the damage to our land," Ms Smith said.
"The Noongar people were fed up ... hopefully our people will get something out of this."
Lawyers confident of success
The claim was filed in the Federal Court last week and was yet to be heard by a judge.
Lawyers representing the group said they were confident the claim would be successful, as their case was based on a precedent set earlier this year in a native title compensation test case.
The High Court awarded $2.5 million in compensation to traditional owners of Timber Creek in the Northern Territory for 170ha of land that had native title extinguished.
They were awarded $15,000 in compensation per hectare, for economic and emotional damages.
Lawyers in the Noongar claim were using the same formula, pursuing $15,000 per hectare for the 19.4 million hectares of extinguished native title on Noongar country.
"$300 billion might sound unreasonable but this is for an area the size of Victoria," Mr Stevenson said.
"This isn't something we plucked out of the air, we have been working on it behind the scenes for months, we've been working with experts to get this figure."
He said the final compensation figure could even exceed his own expectations.
"We may have been a little too conservative, it could have been a little bit larger," he said.
"It's not whether the state can afford it, it's simply that what is owed."
One potential catch
There is a potential sticking point in the case - compensation can only be paid for the native title areas extinguished after the 1975 Racial Discrimination Act was brought into effect.
Mr Stevenson said it was unclear what portion of the land fell into this category, but a team of experts were working to calculate the final figure.
One of the lead solicitors on the Mabo case, Greg McIntyre SC, who is also the president of the Western Australian Law Society, said this factor could greatly reduce the amount of land eligible for compensation.
"I think there are some difficulties about [the Noongar people] being successful in a claim of that kind," he said.
"Lots of the extinguishing of native title for Noongars and in Western Australia generally pre-date the 1975 Racial Discrimination Act.
"It may [however] attract a negotiated result [between the Government and Noongar people]."
The State Government previously offered $1.3 billion to the six clan groups that form the Noongar nation, for access to the remaining 300 hectares in which their native title had not been extinguished.
That agreement was thrown out of court when some elders refused to sign.
Now those same leaders, including Ms Smith, are leading the charge for this new claim.
She said she felt there was solidarity behind this push, but they would continue to consult with all Noongar people.
"They are fully supporting it, they are supporting it all the way, so it's going to be huge for the Noongar people."
Premier says claim 'way over the top'
WA Premier Mark McGowan said his government would fight the claim.
"A $290 billion claim is pretty extreme," he said.
"We will get advice on what the best course is but it sounds way over the top to me."
Mr McGowan said the state government had already reached a deal under the Indigenous Land Use Agreement with the Noongar nation.
"The Noongar settlement has already occurred," he said.
"I don't know the details of it but clearly we've already reached a settlement with the Noongar people."
The South West Aboriginal Land and Sea Council will continue to pursue the Indigenous Land Use Agreements with the State Government, and did not put forward or endorse the compensation claim.